Re: defining field variables for heterogeneous model

classic Classic list List threaded Threaded
5 messages Options
Reply | Threaded
Open this post in threaded view
|

Re: defining field variables for heterogeneous model

Dave Lindeman
You can use field variables with VUMAT (see the fieldOld and fieldNew
arrays).  But you can't simply define your material constants as tabular
functions of the field variables under *USER MATERIAL.  The dependence has
to be defined within the VUMAT (function, lookup table, etc.).

Regards,

Dave

=============================================
Dave Lindeman              [hidden email]
Sr. CAE Specialist         (TEL) 651-733-6383
3M Company                 (FAX) 651-736-7615
=============================================

----- Original Message -----
From: "nysuka" <[hidden email]>
To: <[hidden email]>
Sent: Friday, January 13, 2006 5:45 PM
Subject: [ABAQUS] defining field variables for heterogeneous model


> I have a model with heterogeneous material properties. Running the
> model with 25,000 different material cards always gives me memory
> problems due to the large size. According to the manual, *FIELD
> command can be used to vary the material properties in space by making
> it dependent on field variables. But since I am using *USER MATERIAL
> for a vumat, there is no option to define field variables unlike
> *ELASTIC. Is there another way to get around this?
>
> thank you
>
>
>
>
>
> Community email addresses:
>   Post message: [hidden email]
>   Subscribe:    [hidden email]
>   Unsubscribe:  [hidden email]
>   List owner:   [hidden email]
>
> Shortcut URL to this page:
>   http://groups.yahoo.com/group/abaqus
> Yahoo! Groups Links
>
>
>
>
>
>



Community email addresses:
  Post message: [hidden email]
  Subscribe:    [hidden email]
  Unsubscribe:  [hidden email]
  List owner:   [hidden email]

Shortcut URL to this page:
  http://groups.yahoo.com/group/abaqus 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ABAQUS/

<*> To unsubscribe from this group, send an email to:
    [hidden email]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply | Threaded
Open this post in threaded view
|

regarding centrifugal load

suresh lakshmanan
hi guys,
   
   i am suresh lakshmanan student of ruhr univeristy bochum- Germany working as an intern in an aerodynamics company.
   
  please help me to fix the following problem in abaqus
   
  Problem :
   
  I did the static analysis for a ventilator fan of  a tunnel.
   
  the stress distribution seems to be logic in the result i,e the pattern .. but the value is too high.. in many ways i tried to solve it but i cant... so i need ur suggestions.
   
  Problem description:
   
  1. simple ventilator fan with hub and 6 blades all of same material ( single part)
  2. load ---- only rotational load ( it was 3000 rpm and i gave 314 rad/sec in abaqus)
  3. Boundary condition  ----   ( i encastered the innier surface of the hub)
  4. As i modelled this blade in CATIA in mm and imported in abaqus IS it necessary to follow SI mm unit conventions ?..  i followed that conventions
  5. youngs modulus 210000 N/mm²  , Density   8E-009 Tonne/mm³  ( 8000Kg/m³) ,
  poissons ration 0.3
   
  I am getting the von mises stress around 9.11 e+02  N/mm² but it has to be in the range between 1.20 e+02 to max 2.5 e+02 N/mm²
   
  if u need the result pictures also i can send it.
   
  expecting ur replies.
   
  with regards
  lakshmanan
   
   
   
   
   

               
---------------------------------
Yahoo! Photos – Showcase holiday pictures in hardcover
 Photo Books. You design it and we’ll bind it!

[Non-text portions of this message have been removed]





Community email addresses:
  Post message: [hidden email]
  Subscribe:    [hidden email]
  Unsubscribe:  [hidden email]
  List owner:   [hidden email]

Shortcut URL to this page:
  http://groups.yahoo.com/group/abaqus 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ABAQUS/

<*> To unsubscribe from this group, send an email to:
    [hidden email]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply | Threaded
Open this post in threaded view
|

Re: defining field variables for heterogeneous model

Benz-2
In reply to this post by Dave Lindeman
Wow, 25000 materials !!

In the VUMAT, you are able to use any constitutive behavior you
want. I suggest you find a relation between the spatial coordinates
of Gauss points (COORD(3)) and your effective Ei, Gij and nuij. It
won't take space like 25000 IF-THEN tests...

BeNZ.

--- In [hidden email], "Dave Lindeman" <ddlindeman@m...>
wrote:
>
> You can use field variables with VUMAT (see the fieldOld and
fieldNew
> arrays).  But you can't simply define your material constants as
tabular
> functions of the field variables under *USER MATERIAL.  The
dependence has

> to be defined within the VUMAT (function, lookup table, etc.).
>
> Regards,
>
> Dave
>
> =============================================
> Dave Lindeman              ddlindeman@m...
> Sr. CAE Specialist         (TEL) 651-733-6383
> 3M Company                 (FAX) 651-736-7615
> =============================================
>
> ----- Original Message -----
> From: "nysuka" <nysuka@l...>
> To: <[hidden email]>
> Sent: Friday, January 13, 2006 5:45 PM
> Subject: [ABAQUS] defining field variables for heterogeneous model
>
>
> > I have a model with heterogeneous material properties. Running
the
> > model with 25,000 different material cards always gives me memory
> > problems due to the large size. According to the manual, *FIELD
> > command can be used to vary the material properties in space by
making
> > it dependent on field variables. But since I am using *USER
MATERIAL

> > for a vumat, there is no option to define field variables unlike
> > *ELASTIC. Is there another way to get around this?
> >
> > thank you
> >
> >
> >
> >
> >
> > Community email addresses:
> >   Post message: [hidden email]
> >   Subscribe:    [hidden email]
> >   Unsubscribe:  [hidden email]
> >   List owner:   [hidden email]
> >
> > Shortcut URL to this page:
> >   http://groups.yahoo.com/group/abaqus
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>






Community email addresses:
  Post message: [hidden email]
  Subscribe:    [hidden email]
  Unsubscribe:  [hidden email]
  List owner:   [hidden email]

Shortcut URL to this page:
  http://groups.yahoo.com/group/abaqus 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ABAQUS/

<*> To unsubscribe from this group, send an email to:
    [hidden email]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply | Threaded
Open this post in threaded view
|

Re: regarding centrifugal load

Benz-2
In reply to this post by suresh lakshmanan
1/Check your units
2/get out of the post processing the singularities if the max
stresses are concentrated in a non-physical area,
3/add plasticity.

BenZ.

--- In [hidden email], suresh lakshmanan
<suresh_fusion@y...> wrote:
>
> hi guys,
>    
>    i am suresh lakshmanan student of ruhr univeristy bochum-
Germany working as an intern in an aerodynamics company.
>    
>   please help me to fix the following problem in abaqus
>    
>   Problem :
>    
>   I did the static analysis for a ventilator fan of  a tunnel.
>    
>   the stress distribution seems to be logic in the result i,e the
pattern .. but the value is too high.. in many ways i tried to solve
it but i cant... so i need ur suggestions.
>    
>   Problem description:
>    
>   1. simple ventilator fan with hub and 6 blades all of same
material ( single part)
>   2. load ---- only rotational load ( it was 3000 rpm and i gave
314 rad/sec in abaqus)
>   3. Boundary condition  ----   ( i encastered the innier surface
of the hub)
>   4. As i modelled this blade in CATIA in mm and imported in
abaqus IS it necessary to follow SI mm unit conventions ?..  i
followed that conventions
>   5. youngs modulus 210000 N/mm²  , Density   8E-009 Tonne/mm³  (
8000Kg/m³) ,
>   poissons ration 0.3
>    
>   I am getting the von mises stress around 9.11 e+02  N/mm² but it
has to be in the range between 1.20 e+02 to max 2.5 e+02 N/mm²

>    
>   if u need the result pictures also i can send it.
>    
>   expecting ur replies.
>    
>   with regards
>   lakshmanan
>    
>    
>    
>    
>    
>
>
> ---------------------------------
> Yahoo! Photos – Showcase holiday pictures in hardcover
>  Photo Books. You design it and we'll bind it!
>
> [Non-text portions of this message have been removed]
>







Community email addresses:
  Post message: [hidden email]
  Subscribe:    [hidden email]
  Unsubscribe:  [hidden email]
  List owner:   [hidden email]

Shortcut URL to this page:
  http://groups.yahoo.com/group/abaqus 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ABAQUS/

<*> To unsubscribe from this group, send an email to:
    [hidden email]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply | Threaded
Open this post in threaded view
|

Re: Re: regarding centrifugal load

suresh lakshmanan
thanks for ur suggestions benz , please can u explain in cae how i can do the second step which u described i,r get out of post processing the singularities if the max stresses are concentrated in a non physical area.
   
  even i cant see the max stress in the fan , which is in the result index.

BenZ <[hidden email]> wrote:
  1/Check your units
2/get out of the post processing the singularities if the max
stresses are concentrated in a non-physical area,
3/add plasticity.

BenZ.

--- In [hidden email], suresh lakshmanan
<suresh_fusion@y...> wrote:
>
> hi guys,
>    
>    i am suresh lakshmanan student of ruhr univeristy bochum-
Germany working as an intern in an aerodynamics company.
>    
>   please help me to fix the following problem in abaqus
>    
>   Problem :
>    
>   I did the static analysis for a ventilator fan of  a tunnel.
>    
>   the stress distribution seems to be logic in the result i,e the
pattern .. but the value is too high.. in many ways i tried to solve
it but i cant... so i need ur suggestions.
>    
>   Problem description:
>    
>   1. simple ventilator fan with hub and 6 blades all of same
material ( single part)
>   2. load ---- only rotational load ( it was 3000 rpm and i gave
314 rad/sec in abaqus)
>   3. Boundary condition  ----   ( i encastered the innier surface
of the hub)
>   4. As i modelled this blade in CATIA in mm and imported in
abaqus IS it necessary to follow SI mm unit conventions ?..  i
followed that conventions
>   5. youngs modulus 210000 N/mm²  , Density   8E-009 Tonne/mm³  (
8000Kg/m³) ,
>   poissons ration 0.3
>    
>   I am getting the von mises stress around 9.11 e+02  N/mm² but it
has to be in the range between 1.20 e+02 to max 2.5 e+02 N/mm²

>    
>   if u need the result pictures also i can send it.
>    
>   expecting ur replies.
>    
>   with regards
>   lakshmanan
>    
>    
>    
>    
>    
>
>            
> ---------------------------------
> Yahoo! Photos – Showcase holiday pictures in hardcover
>  Photo Books. You design it and we'll bind it!
>
> [Non-text portions of this message have been removed]
>







Community email addresses:
  Post message: [hidden email]
  Subscribe:    [hidden email]
  Unsubscribe:  [hidden email]
  List owner:   [hidden email]

Shortcut URL to this page:
  http://groups.yahoo.com/group/abaqus 


   
---------------------------------
  YAHOO! GROUPS LINKS

   
    Visit your group "ABAQUS" on the web.
   
    To unsubscribe from this group, send an email to:
 [hidden email]
   
    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

   
---------------------------------
 

 


                       
---------------------------------
Yahoo! Photos
 Got holiday prints? See all the ways to get quality prints in your hands ASAP.

[Non-text portions of this message have been removed]





Community email addresses:
  Post message: [hidden email]
  Subscribe:    [hidden email]
  Unsubscribe:  [hidden email]
  List owner:   [hidden email]

Shortcut URL to this page:
  http://groups.yahoo.com/group/abaqus 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ABAQUS/

<*> To unsubscribe from this group, send an email to:
    [hidden email]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/